1 files changed, 72 insertions, 56 deletions

diff --git a/drivers/kvm/vmx.c b/drivers/kvm/vmx.c
index a05bfa085877..872ca0381fbe 100644
--- a/drivers/kvm/vmx.c
+++ b/drivers/kvm/vmx.c
@@ -85,19 +85,6 @@ static const u32 vmx_msr_index[] = {
 };
 #define NR_VMX_MSR ARRAY_SIZE(vmx_msr_index)
 
-#ifdef CONFIG_X86_64
-static unsigned msr_offset_kernel_gs_base;
-#define NR_64BIT_MSRS 4
-/*
- * avoid save/load MSR_SYSCALL_MASK and MSR_LSTAR by std vt
- * mechanism (cpu bug AA24)
- */
-#define NR_BAD_MSRS 2
-#else
-#define NR_64BIT_MSRS 0
-#define NR_BAD_MSRS 0
-#endif
-
 static inline int is_page_fault(u32 intr_info)
 {
 	return (intr_info & (INTR_INFO_INTR_TYPE_MASK | INTR_INFO_VECTOR_MASK |
@@ -118,13 +105,23 @@ static inline int is_external_interrupt(u32 intr_info)
 		== (INTR_TYPE_EXT_INTR | INTR_INFO_VALID_MASK);
 }
 
-static struct vmx_msr_entry *find_msr_entry(struct kvm_vcpu *vcpu, u32 msr)
+static int __find_msr_index(struct kvm_vcpu *vcpu, u32 msr)
 {
 	int i;
 
 	for (i = 0; i < vcpu->nmsrs; ++i)
 		if (vcpu->guest_msrs[i].index == msr)
-			return &vcpu->guest_msrs[i];
+			return i;
+	return -1;
+}
+
+static struct vmx_msr_entry *find_msr_entry(struct kvm_vcpu *vcpu, u32 msr)
+{
+	int i;
+
+	i = __find_msr_index(vcpu, msr);
+	if (i >= 0)
+		return &vcpu->guest_msrs[i];
 	return NULL;
 }
 
@@ -307,10 +304,10 @@ static void vmx_save_host_state(struct kvm_vcpu *vcpu)
 
 #ifdef CONFIG_X86_64
 	if (is_long_mode(vcpu)) {
-		save_msrs(vcpu->host_msrs + msr_offset_kernel_gs_base, 1);
-		load_msrs(vcpu->guest_msrs, NR_BAD_MSRS);
+		save_msrs(vcpu->host_msrs + vcpu->msr_offset_kernel_gs_base, 1);
 	}
 #endif
+	load_msrs(vcpu->guest_msrs, vcpu->save_nmsrs);
 }
 
 static void vmx_load_host_state(struct kvm_vcpu *vcpu)
@@ -337,12 +334,8 @@ static void vmx_load_host_state(struct kvm_vcpu *vcpu)
 
 		reload_tss();
 	}
-#ifdef CONFIG_X86_64
-	if (is_long_mode(vcpu)) {
-		save_msrs(vcpu->guest_msrs, NR_BAD_MSRS);
-		load_msrs(vcpu->host_msrs, NR_BAD_MSRS);
-	}
-#endif
+	save_msrs(vcpu->guest_msrs, vcpu->save_nmsrs);
+	load_msrs(vcpu->host_msrs, vcpu->save_nmsrs);
 }
 
 /*
@@ -464,41 +457,74 @@ static void vmx_inject_gp(struct kvm_vcpu *vcpu, unsigned error_code)
 }
 
 /*
+ * Swap MSR entry in host/guest MSR entry array.
+ */
+void move_msr_up(struct kvm_vcpu *vcpu, int from, int to)
+{
+	struct vmx_msr_entry tmp;
+	tmp = vcpu->guest_msrs[to];
+	vcpu->guest_msrs[to] = vcpu->guest_msrs[from];
+	vcpu->guest_msrs[from] = tmp;
+	tmp = vcpu->host_msrs[to];
+	vcpu->host_msrs[to] = vcpu->host_msrs[from];
+	vcpu->host_msrs[from] = tmp;
+}
+
+/*
  * Set up the vmcs to automatically save and restore system
  * msrs.  Don't touch the 64-bit msrs if the guest is in legacy
  * mode, as fiddling with msrs is very expensive.
  */
 static void setup_msrs(struct kvm_vcpu *vcpu)
 {
-	int nr_skip, nr_good_msrs;
+	int index, save_nmsrs;
 
-	if (is_long_mode(vcpu))
-		nr_skip = NR_BAD_MSRS;
-	else
-		nr_skip = NR_64BIT_MSRS;
-	nr_good_msrs = vcpu->nmsrs - nr_skip;
+	save_nmsrs = 0;
+#ifdef CONFIG_X86_64
+	if (is_long_mode(vcpu)) {
+		index = __find_msr_index(vcpu, MSR_SYSCALL_MASK);
+		if (index >= 0)
+			move_msr_up(vcpu, index, save_nmsrs++);
+		index = __find_msr_index(vcpu, MSR_LSTAR);
+		if (index >= 0)
+			move_msr_up(vcpu, index, save_nmsrs++);
+		index = __find_msr_index(vcpu, MSR_CSTAR);
+		if (index >= 0)
+			move_msr_up(vcpu, index, save_nmsrs++);
+		index = __find_msr_index(vcpu, MSR_KERNEL_GS_BASE);
+		if (index >= 0)
+			move_msr_up(vcpu, index, save_nmsrs++);
+		/*
+		 * MSR_K6_STAR is only needed on long mode guests, and only
+		 * if efer.sce is enabled.
+		 */
+		index = __find_msr_index(vcpu, MSR_K6_STAR);
+		if ((index >= 0) && (vcpu->shadow_efer & EFER_SCE))
+			move_msr_up(vcpu, index, save_nmsrs++);
+	}
+#endif
+	vcpu->save_nmsrs = save_nmsrs;
 
-	/*
-	 * MSR_K6_STAR is only needed on long mode guests, and only
-	 * if efer.sce is enabled.
-	 */
-	if (find_msr_entry(vcpu, MSR_K6_STAR)) {
-		--nr_good_msrs;
 #ifdef CONFIG_X86_64
-		if (is_long_mode(vcpu) && (vcpu->shadow_efer & EFER_SCE))
-			++nr_good_msrs;
+	vcpu->msr_offset_kernel_gs_base =
+		__find_msr_index(vcpu, MSR_KERNEL_GS_BASE);
 #endif
+	index = __find_msr_index(vcpu, MSR_EFER);
+	if (index >= 0)
+		save_nmsrs = 1;
+	else {
+		save_nmsrs = 0;
+		index = 0;
 	}
-
 	vmcs_writel(VM_ENTRY_MSR_LOAD_ADDR,
-		    virt_to_phys(vcpu->guest_msrs + nr_skip));
+		    virt_to_phys(vcpu->guest_msrs + index));
 	vmcs_writel(VM_EXIT_MSR_STORE_ADDR,
-		    virt_to_phys(vcpu->guest_msrs + nr_skip));
+		    virt_to_phys(vcpu->guest_msrs + index));
 	vmcs_writel(VM_EXIT_MSR_LOAD_ADDR,
-		    virt_to_phys(vcpu->host_msrs + nr_skip));
-	vmcs_write32(VM_EXIT_MSR_STORE_COUNT, nr_good_msrs); /* 22.2.2 */
-	vmcs_write32(VM_EXIT_MSR_LOAD_COUNT, nr_good_msrs);  /* 22.2.2 */
-	vmcs_write32(VM_ENTRY_MSR_LOAD_COUNT, nr_good_msrs); /* 22.2.2 */
+		    virt_to_phys(vcpu->host_msrs + index));
+	vmcs_write32(VM_EXIT_MSR_STORE_COUNT, save_nmsrs);
+	vmcs_write32(VM_EXIT_MSR_LOAD_COUNT, save_nmsrs);
+	vmcs_write32(VM_ENTRY_MSR_LOAD_COUNT, save_nmsrs);
 }
 
 /*
@@ -595,14 +621,6 @@ static int vmx_set_msr(struct kvm_vcpu *vcpu, u32 msr_index, u64 data)
 	case MSR_GS_BASE:
 		vmcs_writel(GUEST_GS_BASE, data);
 		break;
-	case MSR_LSTAR:
-	case MSR_SYSCALL_MASK:
-		msr = find_msr_entry(vcpu, msr_index);
-		if (msr)
-			msr->data = data;
-		if (vcpu->vmx_host_state.loaded)
-			load_msrs(vcpu->guest_msrs, NR_BAD_MSRS);
-		break;
 #endif
 	case MSR_IA32_SYSENTER_CS:
 		vmcs_write32(GUEST_SYSENTER_CS, data);
@@ -620,6 +638,8 @@ static int vmx_set_msr(struct kvm_vcpu *vcpu, u32 msr_index, u64 data)
 		msr = find_msr_entry(vcpu, msr_index);
 		if (msr) {
 			msr->data = data;
+			if (vcpu->vmx_host_state.loaded)
+				load_msrs(vcpu->guest_msrs,vcpu->save_nmsrs);
 			break;
 		}
 		return kvm_set_msr_common(vcpu, msr_index, data);
@@ -1331,10 +1351,6 @@ static int vmx_vcpu_setup(struct kvm_vcpu *vcpu)
 		vcpu->host_msrs[j].reserved = 0;
 		vcpu->host_msrs[j].data = data;
 		vcpu->guest_msrs[j] = vcpu->host_msrs[j];
-#ifdef CONFIG_X86_64
-		if (index == MSR_KERNEL_GS_BASE)
-			msr_offset_kernel_gs_base = j;
-#endif
 		++vcpu->nmsrs;
 	}